NASA-Inspired Houseplant Trick Can Help Cool a Home in Summer

As summer temperatures climb, many people turn straight to air conditioning, but the article says there is a natural alternative that can reduce indoor heat and is backed by NASA research. British gardening expert Craig Morley says the secret to a cooler, more comfortable home may be the plants placed in living rooms and bedrooms.

Morley says houseplants do more than improve the look of a room. Their key cooling mechanism is transpiration, the biological process in which water moves from the soil through the plant to the leaves and stem. As that water reaches tiny pores in the leaves and evaporates, it draws heat out of the surrounding air, creating a cooling effect similar to sweating in humans.

According to NASA, transpiration accounts for about 10 percent of the water in the atmosphere. In 2018, the agency launched a special mission to study how plants on Earth transpire and how they affect nearby temperatures, data now used by urban planners trying to cool dense cities. The same principle, Morley says, works on a smaller scale indoors, where plants can help fight rising temperatures.

To make that work, Morley recommends watering plants generously, since water-stressed plants slow transpiration. He also advises increasing humidity with a tray of wet pebbles or a humidifier, grouping plants together to create a moist microclimate, moving plants to larger pots if roots are cramped, and avoiding pruning during hot months. He says each plant’s light and humidity needs should also be checked.

Morley notes that plant structure matters too, with larger leaves generally releasing more moisture than curled or folded leaves, and mature plants cooling more effectively because of their greater surface area. He recommends seven plants for summer cooling, including snake plant, peace lily, aloe vera, bamboo palm, Boston fern, golden pothos, and spider plant, with pothos and spider plant suggested as low-maintenance options.